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An Effective RAID Data Layout for Object-Based De-duplication backup System

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Chinese Journal of Electronics 2016年第5期25卷 832-840页

作者： YAN Fang TAN Yu'an ZHANG Quanxin WU Fei CHENG Zijing ZHENG Jun School of Computer Science and Technology Beijing Institute of Technology School of Information Beijing Wuzi University Beijing Engineering Research Center of Massive Language Information Processing and Cloud Computing Application Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Space Star Technology CO. LtdChina Academy of Space Technology

We propose an alternative Redundant array of independent disks(RAID) data layout, Asymmetrical grouping data organization(AGDO), for object-based data de-duplication backup system. Object-based data deduplication is an effective solution for detecting duplicate data for compound files. We designed an asymmetrical grouping strategy, the disk in the array are partitioned into different groups, and in each group parallelism data access scheme is adopted, different types of objects are stored in different groups with maybe different group size, it can set and manage dynamic group size by using dynamic disk group adjustment algorithms. The performance of AGDO is evaluated and proved to be sufficient for the continuous storage application. The result is that disk accesses are concentrated in a part of the disks over a long time period and reduces the power consumption to 25% in a 10-disk configuration. Moreover, object-based de-duplication combined with AGDO has great potential in increasing data restoration speed for compound files. We have shown that this combination makes average restoration speed improved 11%.

关键词： Data layout Object-based deduplication backup Energy aware Redundant array of independent disks(RAID)

Rabbet: Using Layout-Aware backup for RAID Reconstruction

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Chinese Journal of Electronics 2017年第4期26卷 710-719页

作者： ZHU Xudong XU Wei MAO Yuxin ZHU Ping Zhejiang Gongshang University Institute of Computing Technology Chinese Academy of Sciences

Once a disk of storage system is failed,RAID mechanism will reconstruct to keep the *** reconstruction leads to a sharp deterioration in I/O performance of RAID, and the storage system cannot provide high performance service for the applications. The Multi-TB disk capacity and high load of the application make the reconstruction last for a very long time. This paper proposes Rabbet, a method accelerating RAID reconstruction using data of backup. Rabbet includes a new RAID reconstruction frame, a RAID layout-aware mapping mechanism for backup, and a reconstruction algorithm. The result of experiments shows that, comparing to the classic DOR methods Rabbet shortens the RAID5 reconstruction process to 13.9%–42.8% and decreases the average response time for applications during reconstruction by 3.2%–14.6%. Rabbet also improves the reliability of storage systems.

关键词： RAID reconstruction backup Layout aware

The backup 2-Median Problem on Block Graphs

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Acta Mathematicae Applicatae Sinica 2014年第2期30卷 309-320页

作者： Yu-kun CHENG Li-ying KANG Hong YAN Zhejiang University of Finance and Economics Department of Mathematics Shanghai University Department of Logistics and Maritime Studies The Hong Kong Polytechnic University

The backup 2-median problem is a location problem to locate two facilities at vertices with the minimum expected cost where each facility may fail with a given probability. Once a facility fails, the other one takes full responsibility for the services. Here we assume that the facilities do not fail simultaneously. In this paper, we consider the backup 2-median problem on block graphs where any two edges in one block have the same length and the lengths of edges on different blocks may be different. By constructing a tree-shaped skeleton of a block graph, we devise an O（n log n q- m）-time algorithm to solve this problem where n and m are the number of vertices and edges, respectively, in the given block graph.

关键词： location theory backup median block graph

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Reliability Modeling of Phased Mission System with Phase backup by Stochastic Petri Net

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Journal of Donghua University(English Edition) 2018年第5期35卷 418-421页

作者： LI Mengzhu YU Haiyue WU Xiaoyue College of Systems Engineering National University of Defense Technology

This paper presents a modeling method by stochastic Petri net for reliability analysis of phased mission system( PMS) with phase backup. The model consisting of petri nets,depicts the system behaviors of unit level,system logic level and phase level. Guard functions of petri nets are used to avoid modeling complexity and make the model flexible to different reliability logical structures. It was shown that the time redundancy within phase and from phase backup for PMS can both be described by use of the proposed model.

关键词： mission reliability phased mission system(PMS) phase backup Petri nets

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Stochastic Modeling of Database backup Policy for a Computer System

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Journal of Software Engineering and Applications 2013年第2期6卷 53-58页

作者： Syouji Nakamura Xufeng Zhao Toshio Nakagawa Department of Business Administration Aichi Institute of Technology Toyota Japan Department of Human Life and Information Kinjo Gakuin University Nagoya Japan

As the computer system has developed much in this highly information-oriented society, database security has become a very important problem and its backup strategies need to be made more efficiently and safety. The image copy method has been used as the most simple and dependable recovery mechanism for media failure. However, this method spends high overhead costs for massive data transmission and much processing time in the normal operation of the database. To cover such weak points, incremental and full backup methods are adopted before updated trucks reach a predetermined level. Moreover, when the number of full backup files exceeded a predetermined level, we stop incremental and full backups and switch it to the image copy. This paper applies cumulative damage model to backup of files in a database system, by putting damage shock by update, failure shock by database failure and damage by dumped files, and considers the tradeoff among overhead costs of image copy and incremental, full backup methods, and discusses analytically an optimal policy for the image copy backup interval. Finally, numerical examples are given in the case of Poisson process and exponential distributions.

关键词： Database Management System Image Copy Full backup Incremental backup Cumulative Process

Fault Detection Based on Hierarchical Cluster Analysis in Wide Area backup Protection System

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Energy and Power Engineering 2009年第1期1卷 21-27页

作者： Yagang ZHANG Jinfang ZHANG Jing MA Zengping WANG 不详

In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated quickly and defined exactly. In our study, global information will be introduced into the backup protection system. By analyzing and computing real-time PMU measurements, basing on cluster analysis theory, we are using mainly hierarchical cluster analysis to search after the statistical laws of electrical quantities' marked changes. Then we carry out fast and exact detection of fault components and fault sections, and finally accomplish fault isolation. The facts show that the fault detection of fault component (fault section) can be performed successfully by hierarchical cluster analysis and calculation. The results of hierarchical cluster analysis are accurate and reliable, and the dendrograms of hierarchical cluster analysis are in intuition.

关键词： wide area backup protection phasor measurement unit PMU wide area measurement system WAMS fault detection cluster analysis

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backup Exec备份解决方案

Windows & Net Magazine（国际中文版） 2004年第5M期 J013-J016页

VERITAS backup Exec 9.1 for Windows Servers VERITAS是Windows平台数据保护解决方案的领导者，它能够为基于Windows平台的服务器环境提供全面的、投资有效的，并且经过认证的保护。backup Exec的基于Web的管理终端和易用的图形用户... 详细信息

VERITAS backup Exec 9.1 for Windows Servers VERITAS是Windows平台数据保护解决方案的领导者，它能够为基于Windows平台的服务器环境提供全面的、投资有效的，并且经过认证的保护。backup Exec的基于Web的管理终端和易用的图形用户界面，以及整合了类似浏览器的视图和出色的向导工具让任何水平的用户都能够容易地实现对各种规模网络环境的数据保护。可选的高性能代理能够支持现在重要的邮件应用和数据库应用。

关键词： VERITAS公司 backup Exec 数据保护数据备份管理控制台